The present invention relates to an air-conditioning register having a shut-off damper for selectively opening and closing an air passage for air-conditioning air.
An air-conditioning register, which delivers air-conditioning air supplied from an air conditioner through an outlet port of an air passage, is incorporated in an instrument panel of a vehicle. By pivoting fins arranged upstream of the outlet port of the air passage in the air-conditioning register, the direction in which the air-conditioning air is delivered through the outlet port is adjusted. A shut-off damper is arranged upstream of the fins in the air passage. The shut-off damper is pivoted about the axis between an open position for opening the air passage and a closed position for closing the air passage.
Shut-off dampers employed in air-conditioning registers include, for example, the shut-off damper described below.
As shown in FIG. 16, a shut-off damper described in Japanese Laid-Open Patent Publication No. 2012-214177 is configured by two components, which are a damper body 51 and a sealing member 53. The damper body 51 is formed in a plate-like shape using hard material. Two clamping pieces 52, which are spaced apart in the direction of the thickness of the damper body 51, are formed in an outer peripheral portion of the damper body 51. The sealing member 53 is formed in an annular shape using soft material such as urethane. The sealing member 53 is clamped by the two clamping pieces 52 of the damper body 51 and thus attached to the outer peripheral portion of the damper body 51. When at the closed position represented by the long dashed double-short dashed lines in FIG. 16, the sealing member 53 is held in contact with an inner wall surface 54a of a retainer 54 to block the flow of air-conditioning air A1. The sealing member 53 of this type of shut-off damper 50 flexes when the shut-off damper 50 is pivoted to the closed position. That is, the sealing member 53 is brought into contact with the inner wall surface 54a of the retainer 54 in a larger area. This reduces the air-conditioning air A1 leaking from between the inner wall surface 54a and the shut-off damper 50.
However, since the shut-off damper 50 is configured by the two components, which are the damper body 51 and the sealing member 53, the costs for the components of the sealing member 53 and the number of assembly steps are increased. This increases the costs for manufacturing the shut-off damper 50.
The sealing member 53 is clamped by the two clamping pieces 52 and thus attached to the damper body 51. This increases the thickness of the shut-off damper 50 by the amount corresponding to the thicknesses of the clamping pieces 52. The increased thickness of the shut-off damper 50 decreases the actual opening area of the outlet port when the shut-off damper 50 is pivoted to the open position represented by the solid lines in FIG. 16. The actual opening area is the area of the portion that does not include projection of the various components (including the shut-off damper 50) arranged in the retainer 54 in an imaginary plane extending perpendicular to the flow direction of the air-conditioning air A1 through the outlet port. As the actual opening area decreases, the resistance to airflow increases. This increases pressure loss and generates noise.
Also, the air-conditioning air A1 becomes separated from a corner portion of the sealing member 53, thus hampering the flow of the air-conditioning air A1. The pressure loss is thus increased.
In contrast, with reference to FIG. 17, a shut-off damper described in Japanese Laid-Open Patent Publication No. 2004-74945 includes a damper body 61 serving as a frame portion and a sealing portion 62, which is softer than the damper body 61. The sealing portion 62 is formed integrally with the damper body 61 to extend at least along an outer peripheral portion of the damper body 61. The sealing portion 62 includes a distal sealing portion 63 and a flexible joint portion 64 for joining the distal sealing portion 63 and the damper body 61 together. The distal sealing portion 63 has a circular cross section and the joint portion 64 has a rectangular cross section. When at the closed position represented by the long dashed double-short dashed lines in FIG. 17, the distal sealing portion 63 is held in contact with an inner wall surface 65a of a retainer 65.
In this type of shut-off damper 60, since the sealing portion 62 is formed integrally with the damper body 61, it is unnecessary to join the sealing member 53 to the shut-off damper 50 illustrated in FIG. 16. This reduces the costs for manufacturing the shut-off damper 60.
As illustrated in FIG. 18, when at the closed position, the joint portion 64 is elastically deformed and the distal sealing portion 63, which has the circular cross section, is pressed against the inner wall surface 65a by elastic restoring force produced by the joint portion 64. This restrains leakage of the air-conditioning air A1 from between the inner wall surface 65a and the shut-off damper 60.
Also, since the shut-off damper 60 does not need to include the two clamping pieces 52 illustrated in FIG. 16, the thickness of the shut-off damper 60 is relatively small. This restrains decrease in the actual opening area of the outlet port caused by the sealing portion 62 when the shut-off damper 60 is at the open position represented by the solid lines in FIG. 17. Correspondingly, the resistance to airflow and the pressure loss are decreased and generation of the noise is restrained.
Such decrease in the resistance to airflow and pressure loss is brought about also by the fact that the cross section of the distal sealing portion 63 has the circular shape and the distal sealing portion 63 thus lacks a corner portion.
The shut-off damper 60 described in Japanese Laid-Open Patent Publication No. 2004-74945, however, includes the thin plate-like joint portion 64, which is formed at a position downstream of the distal sealing portion 63 as illustrated in FIG. 19. There are zones R1 generating turbulence on the opposite sides in the direction of the thickness of the joint portion 64. Therefore, after the air-conditioning air A1 passes the distal sealing portion 63 while flowing along the shut-off damper 60 located at the open position, turbulence may occur in the zones R1 and thus cause pressure loss.